A primary goal of this project is to chemically characterize the carbohydrate chains found on molecules known to be expressed on the somatic cell surface. One example is the fibronectins, a class of proteins occurring in the blood plasma (CIg, beta 2 SB-opsonin) or within the glycocalyx of fibroblasts, glial cells, endothelial cells, trophoblasts and basement membrane (LETS, gal a FSP, CSP). There is gathering evidence that these immunologically related proteins may have cell-specific differences in biological activity. We have evidence that the carbohydrate patterns may be unique to the cell source. The function of the carbohydrate, although unknown, may be related to protection from protease digestion. We also plan to further characterize the placental immunological barrier which separates maternal and fetal tissues during pregnancy. Since it has been previously demonstrated that limited trypsinization of the trophoblastic cells destroys this barrier, rendering the fetal cells subject to cytolysis by maternal lymphocytes in vitro, the cell surface membrane components have been strongly implicated in the phenomenon. Since the trophoblast cells possess an extensive glycocalyx, we propose to chemically define the carbohydrate structures which coat the microvilli of the trophoblastic cells and to identify the proteins to which these structures are attached. Preliminary evidence indicates the presence of highly unusual glucose glycopeptides. The analytical procedures include the use of combined gas-liquid chromatography-chemical ionization-mass spectrometry (GC-CIMS) to examine the composition and linkage sequence of the carbohydrate chains after sequential degradation with glycosyl hydrolases. A significant effort is planned in development of GC-CIMS methodology.